Determining an Active Persona of a User Device

ABSTRACT

A method for determining an active persona of a user device includes determining a first user device state of a user device. The active persona is indicative of a predicted objective of the user of the user device. The first state defines an action currently being performed on the user device and a set of observations corresponding to the user device. The method includes inputting the first user device state to a model and determining the active persona of the user device based on the output of the model. The model is configured to receive a user device state and outputs probability values associated with one or more clusters, each cluster being indicative of one or more items of interest corresponding to the user device. The method further includes performing a procedure using the active persona of the user device.

CROSS REFERENCE TO RELATED APPLICATIONS

This U.S. patent application claims priority under 35 U.S.C. §119(e) toU.S. Provisional Application 61/921,245, filed on Dec. 27, 2013, whichis hereby incorporated by reference in its entirety.

TECHNICAL FIELD

This disclosure relates to methods and apparatuses for determining anactive persona of a user device.

BACKGROUND

User devices, such as smartphones, tablet PCs, cellular telephones, andportable digital assistants have become widespread and essential inconsumers' everyday lives. Moreover, users personalize their userdevices by downloading applications to their device or accessingapplications via a web-browser. Each user device can have multipleusers, and each user can use the device for a number of differentreasons. For example, a user can use a user device for playing games,watching movies, listening to music, checking financial information,editing documents, and messaging friends.

SUMMARY

One aspect of the disclosure provides a method for determining an activepersona of a user device. The active persona is indicative of apredicted objective of the user of the user device. The method includesdetermining a first user device state of a user device. The first statedefines an action currently being performed on the user device and a setof observations corresponding to the user device. The method furtherincludes the first user device state to a model and determining theactive persona of the user device based on the output of the model. Themodel is configured to receive a user device state and outputsprobability values associated with one or more clusters, each clusterbeing indicative of one or more items of interest corresponding to theuser device. The method further includes performing a procedure usingthe active persona of the user device. The method can be performed by aprocessing device.

Implementations of the disclosure may include one or more of thefollowing optional features. In some implementations, the methodincludes capturing a second user device state of the user device andupdating the model based on the first user device state and the seconduser device state. The second user device state is subsequent to thefirst user device state and defines a subsequent action being performedon the user device and one or more subsequent observations. In someexamples, the model is a Hidden Markov Model.

The first user device state may be based on an active process of theuser device. In some implementations, the active process is one of anactive application being executed by the user device, and active mediacontent being played by the user device, or an active search query beingprovided by the user device. Determining the first user device state mayinclude using an inverted index to determine an active cluster to whichthe active process corresponds. The cluster is indicative of an activeitem of interest corresponding to the user device.

In some examples, the method further includes determining a plurality ofitems of interest of the user device, providing the plurality of itemsof interest to a persona server, and receiving

Determining the first user device state may include obtaining outputvalues of one or more peripheral devices of the user device. Performinga procedure using the active persona may include providing the activepersona to a search engine as part of a search query, providing theactive persona to an application server in communication with the userdevice, or arranging a home screen of the user device based on theactive persona.

The active persona may be a vector indicating a plurality ofprobabilities output by the model. Each element of the vector may devicewill transition from a current item of interest to associated with theprobability value provide a probability of transitioning from the firststate to a second state. In these implementations, each element of thevector corresponds to a different state. Obtaining the active personamay include obtaining a vector indicating a plurality of probabilitiesfrom the model and mapping the vector to a category based on one or morerules.

Another aspect of the disclosure provides a user device that determinesits active persona. The user device includes a storage device includingone or more computer readable mediums that store a model that receives auser device state and outputs probability values associated with one ormore clusters. Each cluster is indicative of one or more items ofinterest corresponding to the user device. The user device furtherincludes a processing device executing computer readable instructions.When executed by the processing device, the computer-readableinstructions cause the user device to determine a first user devicestate of a user device, feed the first user device state to the model,obtain an active persona of the user device based on the output of themodel, and perform a procedure using the active persona. The first userdevice state defines an action currently being performed on the userdevice and a set of observations corresponding to the user device. Theactive persona is indicative of a predicted objective of the user of theuser device. This aspect may include one or more of the followingoptional features.

According to some implementations of the present disclosure, thecomputer readable instructions further cause the processing device tocapture a second user device state after determining the active personaof the user device and to update the model based on the first userdevice state and the second user device state. The second user devicestate is subsequent to the first user device state and defines asubsequent action being performed on the user device and one or moresubsequent observations. In some examples, the model is a Hidden MarkovModel.

According to some implementations, the action being performed by theuser device is based on an active process of the user device. The activeprocess is one of an active application being executed by the userdevice, an active media content being played by the user device, or anactive search query being provided by the user device.

In some implementations, determining the first user device stateincludes determining an active cluster to which the active processcorresponds using an inverted index. The active cluster is indicative ofan active item of interest corresponding to the user device. In some ofthese implementations, the computer readable instructions further causethe processing device to determine a plurality of items of interest ofthe user device, provide the plurality of items of interest to a personaserver, and to

Determining the first user device state may include obtaining outputvalues of one or more peripheral devices of the user device. Performinga procedure using the active persona may include providing the activepersona to a search engine as part of a search query, providing theactive persona to an application server in communication with the userdevice, or arranging a home screen of the user device based on theactive persona.

The active persona may be a vector indicating a plurality ofprobabilities output by the model. Each element of the vector mayindicate a probability that the user device will transition from acurrent item of interest to a cluster associated with the probabilityvalue that contains a second item of interest. In these implementations,each element of the vector corresponds to a different state. Obtainingthe active persona may include obtaining a vector indicating a pluralityof probabilities from the model and mapping the vector to a categorybased on one or more rules.

The details of one or more implementations of the disclosure are setforth in the accompanying drawings and the description below. Otheraspects, features, and advantages will be apparent from the descriptionand drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a drawing illustrating an example system of devices fordetermining and using an active persona of a user device.

FIG. 2 is a schematic illustrating example components of a personaserver.

FIG. 3 is a schematic illustrating example components of a user device.

FIG. 4 is a drawing illustrating an example of a Hidden Markov Model.

FIG. 5 is a flow chart illustrating an example set of operations for amethod for determining an active persona of a user device.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

FIGS. 1-3 illustrate an example system 10 for predicting an activepersona 100 of a user device 300 and the components thereof. The system10 can include a persona server 200 (FIG. 2) and one or more userdevices 300 (FIG. 3) in communication with a network 110. In someimplementations, the persona server 200 is configured to provide datathat allows a user device 300 to determine its active persona 100. Anactive persona 100 of a user device 300 can be indicative of anobjective of a user of the device 300 at a time when the user is usingthe device 300. A user device 300 can have one or more users and eachuser can have one or more objectives when using the device 300. Forexample, a family having a mother, a father, and a child may all use thesame tablet computer 300 a. The father may use the tablet computer 300 afor reading the news in the mornings (e.g., “news objective”), watchingsports in the evenings (e.g., “sports fan objective”), and playingviolent video games at night (e.g., “mature video game objective”). Themother may use the tablet computer 300 a for scheduling tasks in themornings (e.g., “planning objective”) and checking stocks in the evening(e.g., “finance objective”). Finally, the child may use the tabletcomputer 300 a for watching child-appropriate movies in the afternoons(e.g., “child movie watcher objective”) and playing educational games inthe evening (e.g., “educational game objective”). The explicitobjectives provided above are provided for example only. Further, theforegoing examples are trends and not necessarily always adhered to bythe users. The user device 300 utilizes the data and a user device stateof the user device 300 to predict the active persona 100 of the userdevice 300. The user device state can include an action currently beingperformed on the user device 300 (e.g., an active application currentlybeing used on the user device 300, an active media content 326 beingplayed by the user device 300, or an active search query 324 beingprovided by the user device 300) and a set of observations correspondingto the user device 300 (e.g., a location of the user device 300, a speedof the user device 300, a day of the week, a time of the day). The userdevice 300 can use the active persona to perform a procedure, such ascommunicating the active persona 100 to a service provider orrearranging the user home screen based on the active persona 100.

By knowing (or likely knowing) the active persona 100 of the device 300,service providers, such as search engines 120, application providers130, and advertisers, can provide more relevant content to the user.Search engines 120 can utilize an active persona 100 of a user toincrease the relevancy of search results. For example, if the userdevice 300 provides a search query 324 of “schedules,” a search engine120 can provide better results to the user device 300 if it knows theactive persona 100 of the user device 300. In particular, the searchengine 120 cannot decipher what the user means when entering the term“schedules.” By having a prediction as to the active persona 100 of theuser, the search engine 120 can better understand the user's intentionswhen he or she enters the term “schedules.” Drawing from the exampleabove, the search engine 120 can return a list of applications thatprovide schedules of the major sports leagues (e.g., NFL, MLB, NHL, andNBA) when the active persona 100 corresponds to that of a sports fan.Similarly, when the active persona 100 of the device 300 corresponds tothat of a “planner,” then the search engine 120 can return a list ofapplications that are directed to scheduling tasks and appointments. Theactive persona 100 of the device 300 can also help services determinewhich advertisements to transmit to the device 300. For example, if theactive persona 100 is “violent video game persona.” a video streamingservice can embed an advertisement for a new first person shooter game.Similarly, if the active persona 100 is “children's games persona,” anapplication server 130 can transmit an advertisement for a newblockbuster cartoon movie. The foregoing examples are not intended tolimit the uses of active personas 100 of a device 300.

In some implementations, the persona server 200 and a user device 300work in combination to determine an active persona 100 of the device300. The persona server 200 can identify clusters 238 that are used toidentify potential active personas 100 of a device 300. A cluster 238can refer to a group of data records that have one or more similarattributes. In some implementations, each cluster 238 contains the sametype of data records. Examples of data records can include, but are notlimited to, application data records, query data records, and media datarecords.

In some implementations, the persona server 200 identifies clusters 238of similar applications 322, search queries 324, or media contents 326.Clusters 238 are clustered based on the attributes of the data recordsbeing clustered. For instance, the persona server 200 can cluster theapplication records according to the application publisher, applicationtype, application subtype, the ratings of the applications, and thepopularity of the applications. Similarly, the persona server 200 cancluster the query records according to the actual query, the location ofthe query, and the action taken in response to the query results.

When the persona server 200 identifies a cluster 238, the persona server200 can also assign a cluster identifier (“cluster ID”) to theidentified cluster 238. Each cluster ID corresponds to a single cluster238 and each cluster 238 has only one cluster ID. As more data recordsare added to a cluster 238, the make-up of the cluster 238 changes, butthe cluster ID of the cluster 238 should remain the same.

In some implementations, the persona server 200 is further configured toindexes 240 corresponding to the clusters 238. In some implementations,the indexes 240 are inverted indexes that associate a data record to thecluster IDs of the clusters 238 to which the data record belongs. Insome implementations, an inverted index of a particular item may berepresented in the following form: <ITEM_ID->[cluster_ID1, cluster_ID2,. . . cluster_ID_n], where there are n clusters that are associated withthe particular item. For instance, if a certain application (e.g., theANGRY BIRDS® application by Rovio Games) belongs to two differentclusters 238 (“Published By Rovio” and “Popular Games”), the twodifferent clusters 238 can be indexed to the data record of certainapplications. In some implementations, each cluster in the invertedindex may have a weight associated therewith. For example, an exampleinverted index of a particular item may be represented in the followingform: <ITEM_ID->[(cluster_ID1, weight1), cluster_ID2, weight2), . . .cluster_ID_n, weight_n)], where there are n clusters that are associatedwith the item. Each weight may be a value indicating a relativeimportance of the cluster to a given item (e.g., relative to all otherpossible item-cluster tuples).

In some implementations, the persona server 200 provides some or all ofthe indexes 240 to the user devices 300. In some of theseimplementations, the persona server 200 selects the indexes 240 that areprovided to the user devices 300 based on items of interest of each userdevice 300. Examples of items of interest can include applications ofthe user device 300, queries/logs of the user device 300, and historiesof media contents 326 played on the user device 300. The user device 300provides the list of the items of interest (or data that is indicativeof the items of interest) to the persona server 200 and the personaserver 200 transmits the indexes 240 relevant to the items of interest.

The user device 300 can utilize the indexes 240, the user device stateof the user device 300, and one or more machine learned models 400 topredict an active persona 100 of the user. In some implementations, eachuser device 300 monitors itself and creates/updates models 400 thatpredict the active persona 100 of the device 300 based on the actionsbeing performed by the user device and the observations of the userdevice 300 at a given time. In some implementations, the machine learnedmodel 400 is a Hidden Markov Model (“HMM”). Other types of machinelearned models 400 may be implemented as well. For example, the userdevice 300 can create/update a Bayesian model to predict theprobabilities of each state.

A machine learned model 400 receives a user device state as input (e.g.,an action being performed on the user device 300, a current time, a dayof the week, accelerometer readings, current active application, mostrecent search query 324 sent by the user device 300) and outputs one ormore predicted clusters 238. In some implementations, each predictedcluster 238 includes a score (e.g., a probability) indicating alikelihood that the user device 300 is in the predicted cluster 238.Thus, in some implementations, an active persona 100 can be representedby a vector of probabilities. For example, an active persona may bedefined by the following vector, AP(C_(j))=[S₀C₀, S₁C₁, S₂C₂, . . . ,S_(n)C_(n)], where AP is the active persona 100 and S_(i) is theprobability that the user device will transition from an item ofinterest in the jth cluster, C_(j), to an item of interest contained inthe ith cluster, C_(j). Additionally or alternatively, the activepersona 100 can be represented by a category to which the vector ofprobabilities maps or matches.

When the user device 300 determines an active persona 100, the userdevice 300 can communicate the active persona 100 to the persona server200 or another server (e.g., a search engine 120 or an applicationserver 130). Furthermore, the user device 300 can take actions based onthe predicted active persona 100. For instance, if the user device 300predicts that the active persona 100 is likely game related (e.g., themost likely transition or transitions is/are to a cluster correspondingto a game), the user device 300 can reconfigure its home screen of theuser device 300 to display icons and widgets of gaming applications.Similarly, if the user device 300 predicts that the active persona 100is likely business related, the user device 300 can reconfigure its homescreen to display icons and widgets of business related applications.

While the persona server 200 may be configured to determine the activepersona 100, the user device 300 can be used to determine the activepersona 100 so that the user device 300 maintains the model 400. In thisway, the user's information such as locations and habits do not need tobe exported from the user device 300, thereby maintaining the user'sprivacy. Furthermore, when transmitting the active persona 100 of theuser to a remote device (e.g., a third party server), the user device300 can conceal the identity of the user and/or the user device 300before transmitting the active persona 100.

FIG. 2 illustrates an example of a persona server 200. In someimplementations, the persona server 200 is a system of one or morecomputing devices. The persona server 200 may be further integrated intoa larger computing system, such as a search engine 120, an applicationserver 130, or an ad server. In an example implementation, the personaserver 200 includes a processing device 210, a network interface 220,and a storage device 230. The processing device 210 can execute aclustering module 212, an indexer 214, and an index selector 216, all ofwhich can be implemented as computer-readable instructions.

The processing device 210 includes one or more physical processors thatexecute computer-readable instructions (e.g., executable computer code)in communication with a memory device (e.g. RAM and/or ROM) that storesthe computer-readable instructions. In implementations where theprocessing device 210 includes two or more processors, the two or moreprocessors can operate in an individual or distributed manner. In someimplementations, some of the executed components are implemented atdifferent physical devices or locations. For instance, the clusteringmodule 212 may execute at a first location/device and the indexer 214and the index selector 216 may execute at a second location/device.

The network interface device 220 includes one or more devices that canperform wired or wireless (e.g., Wi-Fi or cellular) communication.Examples of the network interface device 220 include, but are notlimited to, a transceiver configured to perform communications using theIEEE 802.11 wireless standard, an Ethernet port, a wireless transmitter,and a universal serial bus (USB) port.

The storage device 230 can include one or more computer readable storagemediums (e.g., hard disk drives and/or flash memory drives). The storagemediums can be located at the same physical location or device or atdifferent physical locations or devices. The storage device 230 canstore application records 232, query records 236, media content records234, clusters 238, and indexes 240.

Application data records 232 correspond to known (e.g., previouslydiscovered) applications. An application can refer to computer readableinstructions that cause a computing device to perform a task. In someexamples, an application may be referred to as an “app.” Exampleapplications include, but are not limited to, word processingapplications, spreadsheet applications, messaging applications, mediastreaming applications, social networking applications, and games.

Each application data record 232 can include application metadata thatdefines the attributes of the application. Examples of attributes of anapplication can include, but are not limited to, a name of theapplication, an operating system that the application is programmed for,a number of downloads of the application, a popularity of theapplication, a type of the application, a subtype of the application, arating of the application, a publisher of the application, an expectedusage amount of the application, and a number of uninstalls of theapplication.

Query data records 236 correspond to previously received search queries324. The search queries 324 can be received by a search engine 120associated with the persona server 200 or from a third-party source.Each query data record 236 can include query metadata that definesattributes of a search query 324. Examples of attributes of a searchquery 324 can include, but are not limited to, the query itself, ageographic location of the user device 300 providing the query, and anaction taken in response to the query (e.g., what the user selected).

Media content records 234 correspond to known media contents (e.g.,movies, songs, albums, TV shows). Each media content record 234 caninclude media metadata that defines the attributes of the media content.Examples of attributes of a media content can include, but are notlimited to, a name of the media content, a type of the media content, agenre of the media content, a format of the media content, an author ofthe media content, a publisher of the media content, a popularity of themedia content, a rating of the media content, and a length of the mediacontent.

The clustering module 212 clusters data records. The clustering module212 receives as input a set of data records to be clustered and mayfurther receive a list of one or more attributes by which to cluster thedata records. The output of the clustering module 212 is one or moreclusters 238. The outputted clusters 238 may identify the members (i.e.,data records) of the cluster 238. The clustering module 212 can executeany clustering algorithm, such as k-nearest neighbors, k-meansclustering, bi-clustering, or text-based clustering. The clusteringmodule 212 can cluster each set of the application records 232, thequery records 236, and the media records 234 individually. That is, theclustering module 212 clusters the application records 232 with otherapplication records 232, query records 236 with other query records 236,and media records 234 with other media records 234. The attributes thatthe clustering module 212 uses to cluster the data records can bemanually selected by a human or can be learned using a statisticalprocess, such as principal component analysis (PCA).

The clustering module 212 can cluster the data records in any suitablemanner. In some implementations, the clustering module 212 can initiallycluster data records into general “category clusters.” During this typeof clustering, the clustering module 212 can produce several high-levelclusters 238 based on all available information. The information bywhich the clustering module 212 clusters the data records can includemetadata contained in the data records 232, 236, 238 (e.g., theattributes collected from 3^(rd) party sources or manually added to therecords). In some implementations, this type of clustering can be donein a supervised manner, whereby a user manually selects the attributes,or representative data records by which the data records are clustered.Furthermore, the clustering module 212 can cluster each cluster 238 intosub-clusters 238. When the clustering module 212 completes clusteringthe general clusters 238, the clustering module 212 can continue tocluster each cluster 238 to identify as many levels as desired.Furthermore, the clusters 238 do not need to make “human sense.” Putanother way, the relationships between data records in a sub-cluster 238do not need to be readily apparent to a human observer.

In some implementations, the clustering module 212 can identify possibleclusters 238 by leveraging user activity. For example, the clusteringmodule 212 can focus on items of interest to a given geo-region. Suchclustering can be done by levels, whereby the clustering module 212begins clustering based on country, then based on state/province, thenurban area, then a particular postal code (if useful). In addition togeo-region, the clustering module 212 can identify clusters 238 of datarecords that are common to a group of users based on generalcollaborative filtering. In these scenarios, the clusters 238 can beidentified using anonymized data (i.e., data which cannot be attributedto any particular user).

In some implementations, the clustering module 212 can identifyapplication specific clusters 238. In these implementations, theclustering module 212 can group application data records 232 with acommon publisher, developer, or franchise (e.g., all of the applicationsin the ANGRY BIRDS® series). Further, the clustering module 212 cangroup application data records 232 that are related to a commonfranchise (e.g., include applications with cheat codes for ANGRY BIRDS®,or ANGRY BIRDS® wallpaper themes).

In some implementations, the foregoing clusters 238 can be subdividedbased on other attributes. The clusters 238 can be divided according to,for example, current popularity, long-term popularity, or price. Theclustering module 212 can produce many sets of overlapping clusters 238.For example, clusters 238 relating to “Rovio applications” may have alarge amount of overlap with a cluster 238 relating to the “ANGRYBIRDS*” franchise.

The clustering module 212 further provides a cluster ID to each newlyidentified cluster 238. The clustering module 212 can be configured todetermine whether the cluster 238 is newly formed or merely updated withnew data records. If the cluster 238 is newly formed, the clusteringmodule 212 generates a new cluster ID. The cluster ID can be any uniqueidentifier, such as a string of alphanumeric characters. If a cluster238 is preexisting and merely being updated, the clustering module 212does not generate a new cluster ID. The cluster IDs may or may not haveproperties associated therewith. For example, a “publisher=Rovio”property or a “popular games” property may be associated with thecluster ID. Furthermore, the clustering module 212 can assign a versionto each cluster 238. In this way, when a cluster 238 is updated, theclustering module 212 can increase the version number of the cluster238. The version can be used to differentiate personas generated fromnow outdated clusters 238 if clusters 238 change over time (e.g.,currently popular games). Additionally or alternatively, the clusteringmodule 212 can merge clusters 238 with very high overlap (e.g., morethan 80% or 85% overlap) in order to reduce the index size.

The indexer 214 creates the index 240 based on the identified clusters238. In some implementations, the index 240 is an inverted index. Foreach data record, the indexer 214 identifies the clusters 238 to whichthe data record belongs and creates an index entry 242 based on thecluster IDs of the identified clusters 238 and an identifier of the datarecord (e.g., a record ID). For instance, if a data record “XYZ” is amember of “cluster_A” and of “cluster_B,” the inverted index entry 242of data record XYZ is “XYZ: {cluster_A, cluster_B}.”

In some implementations, the index selector 216 determines which indexentries 242 to transmit to a device 300. The index selector 216 canselect the index entries 242 to transmit in any suitable manner. In someimplementations, the index selector 216 can receive indicators of itemsof interest of a user device 300 from the user device 300. An item ofinterest can include a list of applications 322 executed/accessed by thedevice (referred to “a list of applications”), list of search queries324 provided by the user device 300 (referred to as “list of searchqueries), and/or a list of media contents 326 played by the user device300 (referred to as a “list of media contents 326). The index selector216 can retrieve the index entries 242 corresponding to each of theitems of interest. Further, in some implementations, the index selector216 can cull the index entries 242 based on a number of factors toreduce the number of index entries 242 that are transmitted to the userdevice 300 in the index 240. For example, the index selector 216 keepsindex entries 242 that contain clusters 238 which match to at least aminimum number of user devices 300. For example, if a particularapplication, search query, or media content is extremely rare, then theindex selector 216 does not include the index entry 242 corresponding tothe rare application, search query, or media content in the index 240that the index selector 216 transmits to the user device 300.

In some implementations, the index selector 216 receives values from thedevice 300, whereby the values are indicative of two or moreapplications 322, two or more search queries 324, and/or two or moremedia contents 326. In these implementations, the actual contents of thetransmitting device 300 (i.e., the exact applications installed on thedevice 300 or recent search queries 324 transmitted from the device 300)are obscured from the persona server 200. The transmitting user device300 can determine the values using, for example, a hash table or a bitmask. In such a scenario, the server 200 can maintain a reverse lookuptable that determines possible applications 322, search queries 324,and/or media contents 326 that correspond to a received value. Theserver 200 can then retrieve the index entries 242 of the possibleapplications 322, search queries 324, and/or media contents 326. In someimplementations, the index selector 216 can cull the index entries 242that are transmitted to the user device 300.

FIG. 3 illustrates an example of a user device 300 configured to predictan active persona 100. The example user device 300 can include aprocessing device 310 in communication with a storage device 320, anetwork interface 330, a user interface 340, and one or more peripheraldevices 350. A user device 300 can include other components not shownwithout departing from the scope of the disclosure.

The processing device 310 can include one or more processors thatexecute computer-executable instructions and associated memory (e.g.,RAM and/or ROM) that stores the computer-executable instructions. Inimplementations where the processing device 310 includes more than oneprocessor, the processors can execute in a distributed or individualmanner. The processing device 310 can execute an index requestor 312, amodel builder 314, a behavior monitor 316, and a persona predictor 318,all of which can be implemented as computer-readable instructions.

The storage device 320 can include one or more computer-readable mediums(e.g., hard disk drive or flash memory drive). The storage device 320can be in communication with the processing device 310, such that theprocessing device 310 can retrieve any needed data therefrom. Thestorage device 320 stores the index 240 that the user device 300receives from the persona server 200 and one or more models 400. Thestorage device 320 can further store applications 322, previous searchqueries 324, and media contents 326.

The network interface 330 includes one or more devices that areconfigured to communicate with the network 110. The network interface330 can include one or more transceivers for performing wired orwireless communication. Examples of the network interface 330 caninclude, but are not limited to, a transceiver configured to performcommunications using the IEEE 802.11 wireless standard, an Ethernetport, a wireless transmitter, and a universal serial bus (USB) port.

The user interface 340 includes one or more devices that receive inputfrom and/or provide output to a user. The user interface 340 caninclude, but is not limited to, a touchscreen, a display, a QWERTYkeyboard, a numeric keypad, a touchpad, a microphone, and/or speakers.

Peripheral devices 350 are hardware components that are included in theuser device 300 to perform specific functions. The user device 300 canhave any number of peripheral devices 350, including an accelerometer, agyroscope, a global positioning system (GPS) module, a camera, a videocamera, and/or a thermometer.

The index requestor 312 requests an index 240 from the persona server200. In some implementations, the index requestor 312 scans the userdevice 300 for items of interest. Items of interest can includeapplications 322 installed (native apps) or accessed (web apps) on theuser device 300, search queries 324 sent by the device 300 to a searchengine 120, and media contents 326 stored on or immediately accessibleto the user device 300. In some implementations, the index requestor 312partially obscures each item of interest to protect the privacy of theuser or users of the user device 300. For instance, the index requestor312 can apply a lossy hash function to an indicator of an item ofinterest. Additionally or alternatively, the index requestor 312 canapply a bit mask to one or more bits of the indicator. The indexrequestor 312 transmits the indicators of the items of interest to thepersona server 200. In some implementations, the index requestor 312 caninclude one or more timestamps with each indicator. For example, for anitem of interest, a timestamp can indicate when the item of interest wasloaded onto the device 300 (e.g., when an application 322 was installedor a media content 326 was downloaded), when the item of interest wasoriginated from the device 300 (e.g., when a search query 324 wastransmitted from the device 300), and/or when the item of interest waslast used (e.g., the last time the application 322 was launched, themedia content 326 was played, or the search query 324 was sent to asearch engine 120). In response, the persona server 200 returns an index240 corresponding to the items of interest. Put another way, the personaserver 200 can return an index 240 containing index entries 242 that arekeyed by the items of interest of the user device 300. The indexrequestor 312 can receive the index 240 and store the received index 240on the storage device 320.

The model builder 314 generates and updates one or more machine learnedmodels 400 used to predict the active persona 100 of the device 300. Insome implementations, the machine learned model 400 is a Hidden MarkovModel (HMM) or a Bayesian model. The model builder 314 initially createsthe model 400 based on the possible user device states of the userdevice 300 and updates the model 400 as the user device 300 is used byone or more users. The user device states can correspond to the variousclusters 238 that the user's actions may implicate. For example, theapplications 322 that the user device 300 launches, the media contents326 that the user device 300 plays, and the search queries 324 that theuser device 300 outputs can implicate various cluster IDs of clusters238 identified in the index 240. The implicated clusters 238 may beindicative of the active persona 100 of the user device 300.

The model 400 predicts a transition from the current cluster implicatedby the user device state of the user device 300 based on the currentuser device state of the device 300. The model 400 can take into accountcurrent observations as well as how the user device 300 has been usedhistorically (i.e., the learned element of the model 400). For example,if the user of the user device 300 typically opens an email applicationon weekday mornings and then opens a newspaper application immediatelyafterward, the model 400 learns this behavior. In this way, when themodel 400 receives a set of observations indicating that it is a weekdaymorning and the user has opened up the email application, the model 400can predict that the user device 300 is likely to launch a newspaperapplication 322 shortly thereafter (or another application in the samecluster 238 as the newspaper application), or at least that it is moreprobable that the user will launch a newspaper application 322 asopposed to a gaming application 322. The model 400 can output one ormore probability values corresponding to different clusters that theuser device 300 may transition to (including the current cluster). Insome implementations, the output of the model 400 is structured in avector, whereby each element of the vector represents a differentcluster, and the value at each element is a probability that the userdevice 300 will transition to that cluster.

FIG. 4 illustrates an example of a machine learned model 400. In theillustrated example, the machine learned model 400 is an HMM. The model400 can include n states 410, S={1, . . . , n}(e.g., clusters) and mobservation sets 420, O=[o₁, . . . , o_(t) _(—) _(max)](e.g., userdevice states). In the illustrated example, there are three clusters 410a, 410 b, 410 c and user device states 420 a, 420 b. In the illustratedexample, the arrows 440 between different clusters 410 represent statetransition probabilities, and lines 450 between clusters 410 and theobservations 420 represent output probabilities. The state transitionprobability indicates a likelihood that the user devices 300 changesfrom the current cluster 410 to a next cluster 410. The outputprobabilities represent a likelihood that a given user device state 420corresponds to a given cluster 410. A current cluster 410 can refer tothe current cluster of the user device 300 (e.g., a cluster of anapplication or media content currently being executed/played by the userdevice 300). A user device state 420 can include any number of features,including the last application launched by the user device 300, thestate of the accelerometer, the location of the user device 300, thecurrent weather conditions, the power state of the device 300, theconditions of the user device an hour ago, the conditions of the userdevice 30 minutes ago, or other suitable observations. The model 400predicts the likely next cluster 410 or clusters 410 of the user device300 given the current user device state 420 at a given time. Forexample, at t=0, the phone's screen is off, the previously predictedcluster 410 was “Violent Video Games,” and it is 9 AM on Saturday. Themodel 400 has learned that on Saturday mornings, the persona 100 islikely to correlate to “watch children movies.” As soon as the phonescreen is turned on, based on the previous cluster 410, and the time ofday and the possible personas 100, the model 400 predicts the nextcluster 410 likely correlates to “watch children movies.” This time,however, it is not the child, but rather the father who plays violentgames, the first thing he does is launch a specific game in the “violentvideo game cluster.” In such a scenario, the model 400 updates thecurrent cluster 410 and then predicts the next cluster 410 correspondsto “violent video games.”

The model builder 314 generates the machine learned model 400 (e.g., HMMor Bayesian model) using the cluster IDs identified in the index entries242 as the states 410 of the model 400. In particular, the model builder314 creates a state 410 for each cluster 238 that is to be included inthe model 400. In some implementations, the model builder 314 cananalyze the received index 240 to identify the set of all possibleclusters 238 for the user device 300 and creates a state 410 for eachidentified cluster 238. In other implementations, the model builder 314identifies the set 420 of all possible clusters 238 and selects a subsetof the clusters 238, such that the selected clusters 238 collectivelyinclude all or substantially all of the items of interest of the userdevice 300. In these implementations, the model builder 314 may beconfigured to minimize the amount of intersection of items of interestbetween the selected clusters 238. Initially, the model builder 314 hasnot trained the model 400 with any data. Accordingly, at the inceptionof the model 400, the model builder 314 associates equal probabilitieswith each of the transitions from a particular cluster 410 to each ofthe other possible clusters 410. Furthermore, because the device 300 canreside in multiple clusters 410 at the same time (e.g., a cluster 238for popular applications and a cluster 238 for first person shootergames), the sum of the probabilities of all of the possible transitionsfrom a particular cluster 410 can be greater than one. In someimplementations, the model builder 314 aggregates user behavior or otheractivity data. In these implementations, the model builder 314 utilizesthe aggregated user behavior to seed the initial probabilities of themodel 400, as opposed to all clusters 238 being equally probable.

The model builder 314 trains the models 400 with observationscorresponding to the device 300 and the actions of the user commandingthe user device 300. Examples of observations can include, but are notlimited to, a current time, a day of the week, an active application(i.e., the application currently being used by the user), active mediacontent, an active search query, the output of the accelerometer, avideo signal from the camera, the type of network connection that theuser device 300 is currently using, and the current location of thedevice 300. The types of observations used to train the model 400 canvary based on the type of the user device 300. In addition to the timeof day, the day of the week, and the active application, the designer ofthe model 400 (e.g., a developer) can select which types of observationsto include in the training data. For example, if the user device 300 isa smartphone, the peripheral devices 350 of the user device 300 mayinclude a camera, a gyroscope, an accelerometer, and a globalpositioning system (GPS) receiver. In such a scenario, the model builder314 can be configured to record the output of these peripheral devices350. The output of the gyroscope, accelerometer, and/or GPS devices canbe used to infer whether the user device 300 is in transit, and if so,what type of transit (e.g., running, walking, driving). Similarly, theoutput of the camera can be used to infer the identity of the user ofthe device 300 (e.g., mother, father, or child).

Examples of actions of a user commanding the user device 300 can includea command to turn the device 300 on, a command to launch an application322, a command to play a media content 326, and/or a command to providea search query 324 to a remote server. Further, the lack of a commandfrom the user can be interpreted as an instruction to continueperforming the same function or activity. The model builder 314 treatseach of these commands as transitions between clusters 410 (e.g., fromthe home screen to an application, from an application to anotherapplication, and playing a media file from a media player application).Each time the current cluster 410 of the user device 300 transitions(e.g., the user device 300 launches a new application or sends a searchquery 324), the model builder 314 updates the model 400 with theobservation, the cluster 410 to which the user device 300 transitioned,and the cluster 410 from which the user device 300 transitioned. Whenthe model builder adds new data (e.g., observed conditions and statetransitions) to the HMM 400, the model builder 314 can calculate newprobabilities for all or some of the potential state transitions fromthe previous cluster 410 of the user device 300.

The behavior monitor 316 monitors the user device 300 and the commandsissued by the user. The behavior monitor 316 can execute as a backgroundprocess. The behavior monitor 316 may be configured to monitor thenetwork interface 330, the user interface 340, the peripheral devices350, and/or any applications being executed by the processing device310. The behavior monitor 316 can maintain a set of current observationsbased on the monitoring. For example, the behavior monitor 316 canmonitor whether the user device 300 is communicating over Wi-Fi or overa cellular network, the output of the accelerometer of the user device300 over a recent period of time, the most recent GPS coordinates of theuser device 300, and/or an image captured by the camera of the userdevice 300.

The behavior monitor 316 further monitors the current cluster 410 of thedevice 300. The current state 410 of the user device 300 can define anaction currently being performed on the user device 300. The currentcluster 410 of the device 300 can be represented using a cluster IDcorresponding to the cluster 238 that is currently implicated by theuser device 300. In some scenarios, the current action may implicatemore than one cluster (e.g., an application belongs to a “violent games”cluster and a “popular games” cluster). The behavior monitor 316 canidentify the current cluster 410 by determining the active application322, active media content 326, or active search query 324 andreferencing the corresponding index entry 242 of the inverted index 240.The inverted index 240 outputs the cluster ID or IDs of the cluster 238or clusters 238 to which the active application 322, active mediacontent 326, or active search query 324 belongs. The behavior monitor316 can provide the set of observations to the model builder 314 and thepersona predictor 318.

The persona predictor 318 predicts the active persona 100 of the userdevice 300 based on the current user device state of the user device300. The persona predictor 318 can input the current user device stateof the user device 300 to the machine learned model 400, and the model400 outputs a set of probabilities. Each probability is associated witha different cluster 238. In an example implementation, the model 400 canoutput a vector, AP, in the form of <P(C_(J)->C₀), P₁(C_(J)->C₁),P₁(C_(J)->C₂), . . . P_(N)(C_(J)->C_(N-1)))> where there are N possibleclusters that the user device 300 can transition to from the currentcluster, C_(J), of the device 300, including remaining in the currentcluster (i.e., C_(J)->C_(J)). In some implementations, the activepersona 100 is set equal to the output vector. Put another way, theactive persona 100 can be represented by the combination ofprobabilities of transitioning to each possible cluster from the currentcluster. In some situations, the sum of the probabilities may exceed onebecause the user device 300 can exist in multiple clusters at the sametime. For example, if the user is watching a popular new horror movie,the popular horror movie may implicate a cluster 238 corresponding tonewly released movies and a cluster 238 corresponding to horror movies.

Additionally or alternatively, the persona predictor 318 can match thevectors output by the model 400 to persona categories. Personacategories can be predetermined categories. Examples of predeterminedcategories can include: “productivity applications,” “electronic readerapplications.” “zombie shooter games,” “popular games,” “media playerapplications,” “shopping,” “organization applications,” “play kidsmusic,” “play popular TV shows,” and “searching for movies.” Theforegoing list of categories is provided for example only and anycategory can be used. The persona predictor 318 can match a vector to acategory in any suitable manner. In some implementations, the personapredictor 318 can reference a set of rules for matching the vector to acategory. For example, a rule can state that if the probability that theuser device will transition to an item of interest in a first cluster238 is greater than 0.8, then the output vector matches to category A.Furthermore, in some implementations, the categories do not need to be“human understandable.” The rules for matching a vector to a categorycan be learned over time by a machine learner or hard-coded.

Table 1 illustrates an example use of a model 400 (e.g., an HMM). Themodel 400 receives a current user device state (i.e., the currentcluster of the user and features corresponding to user device 300) anddetermines the active persona 100 based thereon.

TABLE 1 INPUT CURRENT CLUSTER (last output) Time, t Cat1 Cat2 Cat3 Cat40 0 0 0 0 1 0 0 0 0 2 0.95 0 0 0 3 0 1 0 0 . . . N 0 0 0 0.95 FeaturesCluster 5 minutes ago Time, t Cat1 Cat2 Cat3 Cat4 0 0 0 0 0 1 0 0 0 0 20 1 0 0 3 0 0 0 0 . . . N 0 0 0 0 Features Cluster 30 minutes agoTime/step Cat1 Cat2 Cat3 Cat4 0 0 0 0 0 1 0 0 0 0 2 0 1 0 0 3 0 1 0 0 .. . N 0 0 0 1 Features Device features Time, t Idle Screen Accelerometer0 1 0 0 1 1 0 0 2 0 1 0 3 1 0 1 . . . N 0 1 1 User-location in the past30 minutes Time, t Moving fast? Still? At Loc 1 At Loc2 At Loc3 0 0 1 10 0 1 0 1 1 0 0 2 0 1 1 0 0 3 0 0 1 0 0 . . . N 1 0 0 1 0 Time Away fromTime, t home? 0-6 6-9 9-12 12-15 15-18 18-21 21-24 DOW 0 0 1 0 0 0 0 0 0M 1 0 0 1 0 0 0 0 0 M 2 0 0 1 0 0 0 0 0 M 3 0 0 1 0 0 0 0 0 M . . . N 10 1 0 0 1 0 0 F Output NEXT STATE Time, t Cat1 Cat2 Cat3 Cat4 0 0.1 0.10.1 0.1 1 0.8 0.15 0 0.05 2 0 0.95 0 0 3 0 0.95 0 0 . . . N 0 0.1 0.80.1

In the example of Table 1, the user device can operate in four or moreclusters 410 (e.g., Cat1=“News and Weather,” Cat2=“Game Mode,”Cat3=“Entertainment,” Cat4=“Productivity Apps” . . . ). Each of theclusters 410 can correspond to different sets of items of interest(e.g., applications, media contents, and/or queries). Furthermore, Table1 provides information regarding N or more different times (t=0, t=1,t=2, t=3 . . . t=N). The model 400 receives, as input, the currentcluster of the user device 300 (e.g., the current category being used bythe user). The model 400 further receives an observation set 420 (i.e.,features corresponding to the user and/or the user device 300). In theexample of Table 1, the model 400 receives previous clusters of the userdevice 300 (e.g., the cluster of the user device five minutes ago andthirty minutes ago), a present location of the device 300 (e.g., thelocation in the previous thirty minutes), whether the device 300 ismoving quickly at the present location (e.g., is the accelerometersignal indicative of a speed greater than a threshold speed), the statusof the screen, the status of the accelerometer, and the status of thedevice 300 (e.g., idle/in use).

In the illustrated example, at t=0 (i.e., Monday morning betweenmidnight and 6:00 AM), the device 300 is idle and is not accelerating.The user is “quiet” and there is no strong prediction as to the categoryof the device 300. Thus, the active persona 100 may be represented as<0.1, 0.1, 0.1, 0.1 . . . >. At t=1 (i.e., Monday morning at 6 AM), theuser is idle but the model 400 is most likely in Cat1 (e.g., “News andWeather”), but also may be in Cat2 (e.g., “Games”). Thus, the activepersona 100 may be represented by <0.8, 0.15, 0, 0.05 . . . >. Theforegoing active persona 100 may be learned by the model 400 if the usertypically checks the news and/or the weather upon waking up, butsometimes plays a game. At t=0 (i.e., Monday morning at 7:00 AM), theuser is active and currently playing a game. The output of the model 400changes to predict that the user is in Cat2 (e.g., “Games”). In thisinstance, the prediction at t=1 was incorrect. The model builder 314 canupdate the model 400 accordingly, such that the next time the userdevice 300 encounters the same or similar observation set 420, theprobability that the user is operating in a game mode is increased. Att=3 (i.e., Monday morning at 8:00 AM), the user device 300 is at Loc1(e.g., the home of the user) and moving, but not moving fast (i.e., theaccelerometer signal is on, but does not exceeds a threshold). At t=3,the model 400 outputs a prediction that the user device 300 is likely inCat2 (e.g., gaming). The active persona 100 may be <0, 0.95, 0, 0, . .. >. At t=N, (i.e., Friday at 5:00 PM) the user device 300 is idle, butthe user is moving fast. In this scenario, the user may be driving homefrom work (Loc2). At t=5, the user has used the productivityapplications (e.g., email application) in the previous three hours. Themodel 400 predicts that the user is likely to switch to Cat3 (e.g.,“Entertainment), and is less likely to play a game or use a productivityapplication (each with a 10% probability). At t=5, the active persona100 may be <0, 0.1, 0.8, 0.1 . . . >. The example of Table 1 is notintended to limit the scope of the disclosure. The category lists andthe features are provided for example and additional alternativecategories and features may be implemented in the model 400.

The active persona 100 of the user device 300 can be used for manydifferent functions. In some implementations, a search application canrequest the active persona 100 from the persona predictor 318 when thesearch application is launched or otherwise made active. The personapredictor 318 provides an active persona 100 of the user device 300 tothe search application, which in turn includes the active persona 100with the metadata of the search query 324. In this way, when the searchengine 120 executes the search using the search query 324, the activepersona 100 can provide additional context to the search query 324. Forexample, if the search query 324 is (“watch lions”) and the activepersona 100 indicates that the user is more likely (e.g., 0.8probability) searching for sports related content than searching forchildren's educational content (0.05), the search engine 120 can returnsearch results that indicate applications that allow users to watch livesports (e.g., watch the Detroit Lions play football) over applicationsthat have animal related videos (e.g., watch videos of lions). In thissituation, the persona predictor 318 can continue to update the activepersona 100 of the user device 300 as the active persona 100 changes.

In another example, the user may be using a free application (e.g.,music streaming application) that derives revenue from displaying ads tousers. In this example, an application server 130 of the freeapplication can request the active persona 100 of the user from thepersona predictor 318. The persona predictor 318 can provide the activepersona 100 to the application server 130. In response to the activepersona 100, the server 130 can select an advertisement to provide tothe user based on the active persona 100. For instance, if the activepersona 100 indicates that the user is likely to watch a popular TV showafter listening to music, the free application can display or stream anad for a new popular TV show. Alternatively, if the active persona 100indicates that the user is likely to play a violent video game afterlistening to music, then the application server 130 may provide an adfor a new first person shooter game.

In yet another example, the operating system of the user device 300 mayrequest the active persona 100 of the user device 300. The personapredictor 318 can provide the active persona 100 to the operatingsystem, which can use the active persona 100 to reconfigure the homescreen displayed by the user interface 340. For instance, if the activepersona 100 indicates that the user is likely to watch a movie, theoperating system can reconfigure the home screen to display the mediaplayer application icons prominently. Alternatively, if the activepersona 100 indicates that the user is likely to open email or use adocument viewer, the operating system can reconfigure the home screen todisplay business-related application icons prominently.

The active persona 100 can be used for any other number of functions. Inthis way, the use of active personas 100 can enhance the user experienceof the user device 300. Furthermore, in some implementations the usercan manually select his or her active persona 100. In theseimplementations, the user can input his or her active persona 100 via agraphical user interface of the user device 300. The user device 300 canthen use the manually inputted active persona 100 in any of the mannersdescribed above.

Referring now to FIG. 5, an example method 500 for predicting an activepersona 100 of a user device 300 is illustrated. The method 500 isexplained with reference to the components of the user device 300. It isunderstood that any other suitable components may execute the method500.

At operation 510, the behavior monitor 316 captures a current userdevice state of a user device 300. In order to determine the currentuser device state of the user device 300, the behavior monitor 316determines what the active process of the user device 300 is to capturethe current state 410. That is, the behavior monitor 316 can identifythe active application 322, active media content 326, or active searchquery 324. The behavior monitor 316 then references the inverted indexentry 242 of the active process to identify the cluster ID or IDs of theclusters 238 implicated by the active process. The cluster ID or IDsrepresent the current user device state 410 or states 410 of the userdevice 300. As discussed, the persona server 200 may select the indexentries 242 so as to minimize collisions, but there may be overlapbetween one or more clusters 238.

In addition to the active process, the behavior monitor 316 captures thecurrent observations of the user device 300. The behavior monitor 316can capture the states of the network interface device 330, the userinterface 340, and/or the peripheral devices 350. For example, thebehavior monitor 316 can determine whether the user device 300 isoperating on a Wi-Fi network or on a cellular network, the output of theaccelerometer over a previous amount of time (e.g., five minutes), theoutput of the GPS system, the time of the day, and the day of the week.Depending on the capabilities of the device 300 and otherconsiderations, the behavior monitor 316 can capture other currentobservations as well, including a current temperature, the output of thevideo camera, and the amount of ambient light. The behavior monitor 316can maintain a current observation data structure that defines the setof observations that the behavior monitor 316 captures. Each time thebehavior monitor 316 captures a new observation, the behavior monitor316 can update the data structure with the new observation.

At operation 512, the persona predictor 318 inputs the current userdevice state into a model 400. At operation 514, the persona predictor318 obtains the active persona 100 from the model 400. In someimplementations, the model 400 outputs one or more vectors ofprobabilities. As previously indicated, each probability is associatedwith a different cluster and indicates a likelihood that the user device300 will transition to an item of interest corresponding to the cluster.In some implementations, the active persona 100 or personas 100 are setequal to the output vector or vectors. In other implementations, thepersona predictor 318 matches the vector to an active persona categoryto obtain the active persona 100 or personas 100 of the user device 300.

At operation 516, the persona predictor 318 performs a procedure usingthe active persona 100. In some implementations, the persona predictor318 can provide the active persona 100 to a process executing on theuser device 300 (e.g., the operating system of the user device 300) orto a remote device (e.g., application server 130 or an advertisementserver). In some implementations, the persona predictor 318 can providethe active persona 100 to a search application, which in turn includesthe active persona 100 in a search query 324 that it provides to asearch engine 120. In some implementations, the operating system of theuser device 300 can rearrange the home screen of the user device 300 inaccordance with the active persona 100. For instance, if the activepersona 100 indicates that the user is likely to play a violent videogame, the operating system can rearrange the home screen to show iconsof the violent video game on the home screen. In this way, the activepersona 100 can be used to enhance the user's overall experience of theuser device 300.

At operation 518, the behavior monitor 316 captures a new user devicestate of the user device 300. The behavior monitor 316 can monitor theaction of the user of the user device 300 after the persona predictor318 predicts the active persona 100. In some implementations, thebehavior monitor 316 waits until the user device 300 changes the currentactive process (e.g., the user transitions to a different application ormedia content 326) to capture the new user device state. If the userdoes not change the active process for a timeout period (e.g., fiveminutes), the behavior monitor 316 determines that the user device 300remained in the same user device state. In other implementations, thebehavior monitor 316 captures a new user device state of the user device300 in intervals of predetermined length (e.g., every two minutes). Inthese implementations, the new user device state may be the same as thecurrent user device state if the user device 300 does not change theactive process during the predetermined interval. The behavior monitor316 can capture other observations in addition to capturing the newactive process.

At operation 520, the model builder 314 updates the model 400. In someimplementations, the model builder 314 updates the training data of themodel 400 with the current user device state (determined at operation510) and the new user device state (determined at operation 520) ascaptured by the behavior monitor 316. In this way, the model builder 314defines a known transition given a current user state and a subsequentnew user device state.

The method 500 can execute in this manner upon receiving a request foran active persona 100 or at predetermined intervals (e.g., every fiveminutes when the user device 300 is in use). The method 500 is providedfor example only and variations of the method 500 are contemplated.Further, some of the operations may be performed out of order orconcurrently.

Various implementations of the systems and techniques described here canbe realized in digital electronic and/or optical circuitry, integratedcircuitry, specially designed ASICs (application specific integratedcircuits), computer hardware, firmware, software, and/or combinationsthereof. These various implementations can include implementation in oneor more computer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device.

These computer programs (also known as programs, software, softwareapplications or code) include machine instructions for a programmableprocessor, and can be implemented in a high-level procedural and/orobject-oriented programming language, and/or in assembly/machinelanguage. As used herein, the terms “machine-readable medium” and“computer-readable medium” refer to any computer program product,non-transitory computer readable medium, apparatus and/or device (e.g.,magnetic discs, optical disks, memory, Programmable Logic Devices(PLDs)) used to provide machine instructions and/or data to aprogrammable processor, including a machine-readable medium thatreceives machine instructions as a machine-readable signal. The term“machine-readable signal” refers to any signal used to provide machineinstructions and/or data to a programmable processor.

Implementations of the subject matter and the functional operationsdescribed in this specification can be implemented in digital electroniccircuitry, or in computer software, firmware, or hardware, including thestructures disclosed in this specification and their structuralequivalents, or in combinations of one or more of them. Moreover,subject matter described in this specification can be implemented as oneor more computer program products, i.e., one or more modules of computerprogram instructions encoded on a computer readable medium for executionby, or to control the operation of, data processing apparatus. Thecomputer readable medium can be a machine-readable storage device, amachine-readable storage substrate, a memory device, a composition ofmatter affecting a machine-readable propagated signal, or a combinationof one or more of them. The terms “data processing apparatus,”“computing device,” and “computing processor” encompass all apparatus,devices, and machines for processing data, including by way of example aprogrammable processor, a computer, or multiple processors or computers.The apparatus can include, in addition to hardware, code that creates anexecution environment for the computer program in question, e.g., codethat constitutes processor firmware, a protocol stack, a databasemanagement system, an operating system, or a combination of one or moreof them. A propagated signal is an artificially generated signal, e.g.,a machine-generated electrical, optical, or electromagnetic signal thatis generated to encode information for transmission to suitable receiverapparatus.

A computer program (also known as an application, program, software,software application, script, or code) can be written in any form ofprogramming language, including compiled or interpreted languages, andit can be deployed in any form, including as a stand-alone program or asa module, component, subroutine, or other unit suitable for use in acomputing environment. A computer program does not necessarilycorrespond to a file in a file system. A program can be stored in aportion of a file that holds other programs or data (e.g., one or morescripts stored in a markup language document), in a single filededicated to the program in question, or in multiple coordinated files(e.g., files that store one or more modules, sub programs, or portionsof code). A computer program can be deployed to be executed on onecomputer or on multiple computers that are located at one site ordistributed across multiple sites and interconnected by a communicationnetwork.

The processes and logic flows described in this specification can beperformed by one or more programmable processors executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read only memory ora random access memory or both. The essential elements of a computer area processor for performing instructions and one or more memory devicesfor storing instructions and data. Generally, a computer will alsoinclude, or be operatively coupled to receive data from or transfer datato, or both, one or more mass storage devices for storing data, e.g.,magnetic, magneto optical disks, or optical disks. However, a computerneed not have such devices. Moreover, a computer can be embedded inanother device, e.g., a mobile telephone, a personal digital assistant(PDA), a mobile audio player, a Global Positioning System (GPS)receiver, to name just a few. Computer readable media suitable forstoring computer program instructions and data include all forms ofnon-volatile memory, media and memory devices, including by way ofexample semiconductor memory devices, e.g., EPROM, EEPROM, and flashmemory devices; magnetic disks, e.g., internal hard disks or removabledisks; magneto optical disks; and CD ROM and DVD-ROM disks. Theprocessor and the memory can be supplemented by, or incorporated in,special purpose logic circuitry.

To provide for interaction with a user, one or more aspects of thedisclosure can be implemented on a computer having a display device,e.g., a CRT (cathode ray tube), LCD (liquid crystal display) monitor, ortouch screen for displaying information to the user and optionally akeyboard and a pointing device, e.g., a mouse or a trackball, by whichthe user can provide input to the computer. Other kinds of devices canbe used to provide interaction with a user as well; for example,feedback provided to the user can be any form of sensory feedback, e.g.,visual feedback, auditory feedback, or tactile feedback; and input fromthe user can be received in any form, including acoustic, speech, ortactile input. In addition, a computer can interact with a user bysending documents to and receiving documents from a device that is usedby the user, for example, by sending web pages to a web browser on auser's client device in response to requests received from the webbrowser.

One or more aspects of the disclosure can be implemented in a computingsystem that includes a backend component, e.g., as a data server, orthat includes a middleware component, e.g., an application server, orthat includes a frontend component, e.g., a client computer having agraphical user interface or a Web browser through which a user caninteract with an implementation of the subject matter described in thisspecification, or any combination of one or more such backend,middleware, or frontend components. The components of the system can beinterconnected by any form or medium of digital data communication,e.g., a communication network. Examples of communication networksinclude a local area network (“LAN”) and a wide area network (“WAN”), aninter-network (e.g., the Internet), and peer-to-peer networks (e.g., adhoc peer-to-peer networks). Communication networks can include cellularnetworks and/or telephone networks.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other. In someimplementations, a server transmits data (e.g., an HTML page) to aclient device (e.g., for purposes of displaying data to and receivinguser input from a user interacting with the client device). Datagenerated at the client device (e.g., a result of the user interaction)can be received from the client device at the server.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of the disclosure or of what maybe claimed, but rather as descriptions of features specific toparticular implementations of the disclosure. Certain features that aredescribed in this specification in the context of separateimplementations can also be implemented in combination in a singleimplementation. Conversely, various features that are described in thecontext of a single implementation can also be implemented in multipleimplementations separately or in any suitable sub-combination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asub-combination or variation of a sub-combination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. In certain circumstances, multi-tasking and parallel processingmay be advantageous. Moreover, the separation of various systemcomponents in the embodiments described above should not be understoodas requiring such separation in all embodiments, and it should beunderstood that the described program components and systems cangenerally be integrated together in a single software product orpackaged into multiple software products.

A number of implementations have been described. Nevertheless, it willbe understood that various modifications may be made without departingfrom the spirit and scope of the disclosure. Accordingly, otherimplementations are within the scope of the following claims. Forexample, the actions recited in the claims can be performed in adifferent order and still achieve desirable results.

1. A method comprising: determining, by a processing device, a firstuser device state of a user device, the first user device state definingan action currently being performed on the user device and one or moreobservations corresponding to the user device; inputting, by theprocessing device, the first user device state to a model that receivesa user device state and outputs probability values associated with oneor more clusters, each cluster being indicative of one or more items ofinterest corresponding to the user device; determining, by theprocessing device, an active persona of the user device based on theoutput of the model, the active persona being indicative of a predictedobjective of a user of the user device; and performing, by theprocessing device, a procedure using the active persona of the userdevice.
 2. The method of claim 1, further comprising: capturing, by theprocessing device, a second user device state after determining theactive persona of the user device the second user device state beingsubsequent to the first user device state and defining a subsequentaction being performed on the user device and one or more subsequentobservations; and updating, by the processing device, the model based onthe second user device state and the first user device state.
 3. Themethod of claim 1, wherein the model is a Hidden Markov Model.
 4. Themethod of claim 1, wherein the action being performed by the user deviceis based on an active process of the user device.
 5. The method of claim4, wherein the active process is one of an active application beingexecuted by the user device, an active media content being played by theuser device, or an active search query being provided by the userdevice.
 6. The method of claim 4, wherein determining the first userdevice state includes determining an active cluster to which the activeprocess corresponds using an inverted index, the active cluster beingindicative of an active item of interest corresponding to the userdevice.
 7. The method of claim 6, further comprising: determining, bythe processing device, a plurality of items of interest of the userdevice, each item of interest indicating one of an application installedon the user device, a media content previously played on the userdevice, or a search query previously provided from the user device;providing, by the processing device, the plurality of items of interestto a persona server; and receiving, by the processing device, theinverted index from the persona server, the inverted index containing aplurality of inverted index entries, each inverted index entrycorresponding to one of the items of interest and identifying one ormore clusters to which the item of interest belongs.
 8. The method ofclaim 1, wherein determining the first user device state includesobtaining output values of one or more peripheral devices of the userdevice.
 9. The method of claim 1, wherein performing the procedure usingthe active persona includes communicating the active persona to a searchengine as part of a search query.
 10. The method of claim 1, whereinperforming the procedure using the active persona includes communicatingthe active persona to an application server in communication with theuser device.
 11. The method of claim 1, wherein performing the v usingthe active persona includes rearranging a home screen of the user devicebased on the active persona.
 12. The method of claim 1, wherein theactive persona is a vector indicating the probabilities output by themodel, wherein each element of the vector indicates a probability thatthe user device will transition from a current item of interest to acluster associated with the probability value that contains a seconditem of interest.
 13. The method of claim 1, wherein obtaining theactive persona includes: obtaining a vector indicating the probabilitiesoutput by the model, each element of the vector indicating a probabilitythat the user device will transition from a current item of interest toa cluster associated with the probability value that contains a seconditem of interest; and mapping the vector to a category based on one ormore rules.
 14. A user device comprising: a storage device including oneor more computer readable mediums that store a model that receives auser device state of a user device and outputs probability valuesassociated with one or more clusters, each cluster being indicative ofone or more items of interest corresponding to the user device; and aprocessing device, the processing device executing computer-readableinstructions that when executed by the processing device cause the userdevice to: determine a first user device state of the user device, thefirst user device state defining an action currently being performed onthe user device and one or more observations corresponding to the userdevice; input the first user device state to the model; determine anactive persona of the user device based on the output of the model, theactive persona being indicative of a predicted objective of the user ofthe user device; and perform a procedure using the active persona of theuser device.
 15. The user device of claim 14, wherein the computerreadable instructions further cause the processing device to: capture asecond user device state after determining the active persona of theuser device the second user device state being subsequent to the firstuser device state and defining a subsequent action being performed onthe user device and one or more subsequent observations; and update themodel based on the first user device state and the second user devicestate.
 16. The user device of claim 14, wherein the model is a HiddenMarkov Model.
 17. The user device of claim 14, wherein the action beingperformed by the user device is based on an active process of the userdevice.
 18. The user device of claim 17, wherein the active process isone of an active application being executed by the user device, anactive media content being played by the user device, or an activesearch query being provided by the user device.
 19. The user device ofclaim 18, wherein determining the first user device state includesdetermining an active cluster to which the active process correspondsusing an inverted index, the active cluster being indicative of anactive item of interest corresponding to the user device.
 20. The userdevice of claim 19, wherein the computer readable instructions furthercause the processing device to: determine a plurality of items ofinterest of the user device, each item of interest indicating one of anapplication installed on the user device, a media content previouslyplayed by the user device, or a search query previously provided fromthe user device; provide the plurality of items of interest to a personaserver; and receive the inverted index from the persona server, theinverted index containing a plurality of inverted index entries, eachinverted index entry corresponding to one of the items of interest andidentifying one or more clusters to which the item of interest belongs.21. The user device of claim 14, wherein determining the first userdevice state includes obtaining output values of one or more peripheraldevices of the user device.
 22. The user device of claim 14, whereinperforming the procedure using the active persona includes communicatingthe active persona to a search engine as part of a search query.
 23. Theuser device of claim 14, wherein performing the procedure using theactive persona includes communicating the active persona to anapplication server in communication with the user device.
 24. The userdevice of claim 14 wherein performing the procedure using the activepersona includes arranging a home screen of the user device based on theactive persona.
 25. The user device of claim 14, wherein the activepersona is a vector indicating the probabilities output by the model,wherein each element of the vector indicates a probability that the userdevice will transition from a current item of interest to a second itemof interest indicated by a cluster associated with the probabilityvalue.
 26. The user device of claim 14, wherein obtaining the activepersona includes: obtaining a vector indicating the probabilities outputby the model, each element of the vector indicating a probability thatthe user device will transition from a current item of interest to asecond item of interest indicated by a cluster associated with theprobability value; and mapping the vector to a category based on one ormore rules.